I. Field of the Invention
The present invention relates to a circuit to improve immunity performance in a network.
II. Description of Related Art
Most modern day vehicles include a network for controlling the electronic devices within the vehicle. Two common networks include the Can Area Network (CAN) and the Flex-Ray network.
An exemplary prior art CAN termination without terminal resistor is illustrated in FIG. 1 and includes a CAN driver 10 having differential input/output signal lines 12. The signal lines 12 are connected through a common mode choke 14 to a signal harness 16 which interconnects the CAN driver 10 to the various electronic devices within the vehicle.
Most vehicle networks, furthermore, operate at a predetermined frequency, e.g. 500 kHz for CAN. In order to reduce high frequency noise, a terminal capacitor 18 is typically connected between each signal line 12 and ground on the side of the common mode choke 14 opposite to the driver 10.
The common mode choke 14 in the network is designed to reduce emission noise. However, in some instances, the inductance of the common mode choke 14 together with the stray capacitance 11 of the driver 10 creates an LC resonance. That resonance, in turn, can cause communication errors, particularly during the immunity testing of the network, such as Bulk Current Injection (BCI) testing.